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| United States Patent |
5,145,700
|
|
Von Lempke
|
September 8, 1992
|
Process for preparing a soya food product
Abstract
The invention provides a process for preparing a soya food product
including the steps of providing a soya concentrate, and pre-mixing the
soya concentrate with a composition including organic flavorants, an amino
acid supplementation, an extract of a spice and vitamins. The pre-mixed
product is then mixed with water at a temperature below 15.degree. C. and
then allowed to soak for a period of time sufficient to allow the soya
concentrate substantially to absorb the composition. The process may
further include a par-cooking step where the product is partially cooked
by frying in an oil or fat medium at a temperature above 170.degree. C.
The process may also include a cooling step where the product is crust
frozen at a temperature below -100.degree. C.
| Inventors:
|
Von Lempke; Frederick E. (170 Derby Road, Kensington, Johannesburg, Transvaal, ZA)
|
| Appl. No.:
|
709576 |
| Filed:
|
May 29, 1991 |
Foreign Application Priority Data
| Current U.S. Class: |
426/240; 426/311; 426/507; 426/634 |
| Intern'l Class: |
A23L 001/00 |
| Field of Search: |
426/634,240,802,507,656,311
|
References Cited
U.S. Patent Documents
| 3925568 | Dec., 1975 | Rao et al. | 426/634.
|
| 4103034 | Jul., 1978 | Ronai et al. | 426/802.
|
| 4764385 | Aug., 1988 | Butland | 426/240.
|
Primary Examiner: Yeung; George
Attorney, Agent or Firm: Michael Best & Friedrich
Claims
I claim:
1. A process for preparing a soya food product including the steps of;
(a) providing a soya concentrate,
(b) pre-mixing the soya concentrate with a composition including organic
flavourants, an amino acid supplementation, an extract of a spice and
vitamins,
(c) mixing the product of step (b) with water at a temperature below
15.degree. C., and
(d) soaking the product of step (c) for a period of time sufficient to
allow the soya concentrate substantially to absorb the composition.
2. A process according to claim 1 which further includes a partial cooking
step
(e) wherein the product of step (d) is partially cooked by frying in an oil
or fat medium at a temperature above 170.degree. C.
3. A process according to claim 1 which further includes a cooling step
(f) wherein the product of step (d) is crust frozen at a temperature below
-100.degree. C.
4. A process according to claim 2 wherein the partial cooking step (e) is
carried out at a temperature between 170.degree. C. and 195.degree. C.
5. A process according to claim 3 wherein the cooling step (f) is carried
out at a temperature between -100.degree. C. and -130.degree. C.
6. A process according to claim 1 wherein the water of step (c) is provided
at a temperature between 6.degree. and 10.degree. C.
7. A process according to claim 1 wherein step (c) is carried out for
between 15 and 20 minutes.
8. A process according to claim 1 wherein step (d) is carried out for
between 15 and 20 minutes.
9. A process according to claim 1 wherein the composition of step (b)
further includes at least one mineral.
10. A process according to claim 1 wherein the composition of step (b)
further includes a cake flour and a binder.
11. A process according to claim 1 wherein the amino acid supplementation
of the composition of step (b) includes between 2.25 and 2.75% weight
lysine, between 0.5 and 0.7% weight methionine and between 0.04 and 0.06%
weight tryptophan based on the weight of the total soya food product.
12. A process according to claim 11 wherein the amino acid supplementation
of the composition of step (b) includes 2.5% weight lysine, 0.6% weight
methionine and 0.05% weight tryptophan based on the weight of the total
soya food product.
13. A process according to claim 2 which includes a further cooking stage
wherein the product is further cooked in a humidified environment.
14. A process according to claim 1 wherein the food product is packed and
then irradiated using a dose of gamma radiation.
15. A process according to claim 14 wherein the dose of gamma radiation is
2 kilo grays.
16. A process for preparing a soya food product including the steps of;
(a) providing a soya concentrate,
(b) pre-mixing the soya concentrate with a composition including organic
flavourants, an amino acid supplementation, an extract of a spice and
vitamins,
(c) mixing the product of step (b) with water at a temperature below
15.degree. C., and
(d) soaking the product of step (c) for a period of time sufficient to
allow the soya concentrate substantially to absorb the composition,
(e) partially cooking the product of step (d) by frying in an oil or fat
medium at a temperature above 170.degree. C., and
(f) crust freezing the product of step (e) at a temperature below
-100.degree. C.
17. A process according to claim 16 wherein prior to step (f) the product
is fan cooled to a temperature below 25.degree. C.
Description
BACKGROUND OF THE INVENTION
This invention relates to a process for preparing a food product from soya
which has the appearance and taste of real animal meats such as beef,
chicken and fish. Typically the food product will be in the form of meat
balls, sausages, hamburger patties, meat loafs, schnitzels, steaks and
fish rissoles. In the past, the products of such processes suffered what
is commonly called "flavour fatigue". This means that a person eating the
product will experience unpleasant after-tastes. Past processes have also
produced products with a relatively short shelf-life thus decreasing their
marketability.
SUMMARY OF THE INVENTION
According to the present invention there is provided a process for
preparing a soya food product including the steps of;
(a) providing a soya concentrate,
(b) pre-mixing the soya concentrate with a composition which includes
organic flavourants, an amino acid supplementation, an extract of a spice,
and vitamins,
(c) mixing the product of step (b) with water at a temperature below
15.degree. C., and
(d) allowing the product of step (c) to soak for a period of time
sufficient to allow the soya concentrate to substantially absorb the
composition of step (b).
Further according to the invention the process further comprises either one
or both of the following steps;
(e) a partial cooking step wherein the product of step (d) is partially
cooked by frying in an oil or fat medium at a temperature above
170.degree. C. and
(f) a cooling step wherein the product of step (b) is crust frozen at a
temperature below -100.degree. C.
Preferably the process will include both the par-cooking step followed by
the cooling step.
DETAILED DESCRIPTION OF THE INVENTION
Before soya beans can be used in any processed soya food product, they are
usually crushed, de-fatted and de-husked. Textured soya concentrate (TSC)
and textured vegetable protein (TVP) and soya isolate are products freely
available on the market and consist basically of crushed soya beans which
have been de-fatted and de-husked. TSC, TVP, soya isolate and mixtures
thereof are examples of ground soya which will, for the purposes of this
specification, be referred to as "soya concentrate".
In a pre-mixing stage the soya concentrate is mixed with a composition
which includes organic flavourants, an amino acid supplementation, an
extract of spices and vitamins.
Numerous organic flavourants constitute a particular composition which has,
for example, the taste of beef. By means of trial and error, combinations
of different organic flavourants are tested for a desirable taste, and
then, further tested for "flavour fatigue". Gas chromatographic methods
are helpful in doing initial determinations of organic flavourants which
are likely to taste like the particular real meat. These organic
flavourants may comprise up to 50 or even more specific organic chemicals.
The amino acid supplementation will preferably comprise between 2.25 and
2.75%, more preferably 2.5% lysine, between 0.5 and 0.7%, more preferably
0.6% methionine and between 0.04 and 0.06%, more preferably 0.05%
tryptophan by weight of the total soya mixture. The soya concentrate in
its original form consists of about 50% by weight protein on a dry basis,
the balance being carbohydrates, fibre and ash. The object of adding the
amino acid supplementation is to bring the net protein utilization (NPU)
value up to a minimum of 60%. The NPU value represents the percentage of
protein in a product in a form which is readily taken up by the body.
Another biological test commonly done on proteinaceous products is the
protein efficiency ratio (PER). A common standard for PER value is that of
casein which is a protein of milk. If casein is taken to have a 100% PER
value then the object of adding the amino acid supplementation to the
product of the invention is to bring the PER value to 200%. The soya
concentrate will have an amount of protein in it which will vary according
to its source. Typically a batch of soya concentrate originating from a
particular source will be analyzed to determine the percentage protein in
it. The amino acid supplementation will then be adjusted to give a desired
PER of the product.
The spice flavourants which form part of the composition in the pre-mixing
stage, are not natural spices. Natural spices are usually contaminated
with a host of bacteria and molds. Extracts of spices are used, the use of
which render the product much more bacteria free, thus improving the
shelf-life of the product. However, if natural spices of strictly
controlled quality are obtainable they can also be used in the composition
and for the purposes of this specification can be considered to be
extracts of spices. Extracts of spices will also, for the purposes of this
specification include extracts of fresh vegetables for example onion.
Vitamins also form an essential part of the composition. The variety and
amount of vitamins used are typically determined so as to closely resemble
and even exceed that of the real meat, fish or poultry that the product is
intended to resemble.
Optionally cake flour, binders such as egg albumin and wheat glutin, and
minerals such as salt, zinc, iron or potassium can form part of the
composition of the pre-mixing stage.
The next part of the process is the mixing step. Here the product of the
pre-mixing stage is mixed with water, the water being at a temperature
below 15.degree. C. Typically the water will be at a temperature between
6.degree. and 10.degree. C. The water is added to the mixture at this low
temperature in order to render the mixture formable in a forming machine.
If the mixing were to be carried out at a higher temperature the mixture
would absorb more moisture than if carried out at the lower temperature
causing the product to gel and fall apart in later processing. Typically
the mixing is carried out for between 15 and 20 minutes. At this stage the
protein concentration of the product is between 15% and 18% by weight on a
wet basis of the product.
The soya mixture is then allowed to soak in this flavour system with water
for a sufficient period so as to allow the soya mixture to absorb the
flavourants and retain them during subsequent processing. Typically the
period will be between 15 and 20 minutes. It is not necessary to take
positive steps, e.g. refrigeration, during the mixing and soaking steps to
maintain the temperature below 15.degree. C. Generally though the cold
water will maintain the product below 15.degree. C.
The next step in the process is the partial cooking stage. The purpose of
this stage is to form a crust or "seal" around the product thus "sealing
in" and enhancing the flavourants referred to above. The cooking is
usually carried out by means of a conveyor frier, using vegetable oil or
animal fat, operating at a temperature above 170.degree. C. Preferably the
temperature will be between 175.degree. and 195.degree. C. Preferably the
oil or fat also contains the organic flavourants and extract of spices
referred to above.
Following this step there is a cooling stage. The product can be fan cooled
to a temperature of below 25.degree. C. before entering a nitrogen freezer
operating at an internal temperature of below -100.degree. C. Typically
the internal temperature of the nitrogen freezer will be between
-100.degree. C. and -130.degree. C. There is an economic reason for fan
cooling the product which is to reduce the amount of nitrogen required in
the subsequent nitrogen freezing of the product. The purpose of the
freezing step is to "crust freeze" the product which prevents spoilage
after cooking. The product can then be removed and placed in a normal
freezer to freeze the product solid.
In accordance with another aspect of the invention is a sauce, consisting
of a soya concentrate with the amino acid supplementation as described
above, together with additional flavourants for example chili, curry,
tomato and onion, beef and onion, steak and onion etc. The product of the
above process, when cooked in such a sauce, shows a weight gain in excess
of 8% and can be as high as 15%. Normal meat products will lose from 15 to
30% of their weight during normal cooking procedures. The sauce will
preferably be in a powder form to which the user can add water prior to
cooking.
As an alternative to or prior to the freezing step of the process, the
par-cooking step may be extended until the product is fully cooked.
Typically the continuous frying conveyer will be extended into a dip tank
containing the sauce as described above or the sauce may be sprayed onto
the product, before entering a hot air and humidity tunnel which has a
variable control on both temperature and humidity. Such an extension of
the partial cooking step renders the product fully cooked, the texture
enhanced, succulent and juicy and substantially microbiologically sterile.
The product may then be packed in any suitable fashion, such as being
canned or hermetically sealed under vacuum or gas. This packaged product
will then preferably be irradiated with a dose of gamma radiation.
Typically the dose of gamma irradiation will be 2 kilo grays. The gamma
irradiation will render the product in a condition which will not spoil
for approximately six months to a year even when the product is not
refrigerated.
EXAMPLE
A soya concentrate of TSC (textured soya concentrate) and TVP (textured
vegetable protein) was pre-mixed with a composition which included
(a) a roast beef organic flavourant (2.8% w/w),
(b) an amino acid supplementation of lysine (2.5%), methionine (0.6% w/w)
and tryptophan (0.05% w/w),
(c) dehydrated fresh onion (7.0% w/w),
(d) a vitamin mix (0.7% w/w) of nicotinic acid, riboflavin, ascorbic acid,
vitamin A acetate, vitamin B6 and vitamin B12,
(e) egg albumin (5.8% w/w) and wheat glutin (0.4% w/w) as binders, and
(f) cake flour (5.0% w/w).
All percentages are by weight of the total product including the soya
concentrate.
Water (24% w/w) at a temperature of 6.degree. C. was added to the pre-mix
and mixed for 15 minutes. The product was allowed to soak for 20 minutes.
The product was then put into a forming machine which formed the product
into shapes which resembled meat balls. The product was then put on a
conveyor frier. The frier used vegetable oil at a temperature of
180.degree. C. The vegetable oil had the roast beef organic flavourants
and extract of onion added to it. The product at this stage was partially
cooked and had a crust surrounding it. The product was then fan cooled to
a temperature of 22.degree. C. and then put through a nitrogen freezer
operating at -120.degree. C. This froze the crust of the product. The
crust frozen product was then put into a normal freezer so as to freeze
the product solid.
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